What is actually needed to quantum-compute with harmonic oscillators?

Zusammenfassung

To implement quantum computers on harmonic-oscillator-liked systems, the conventional
approach is to: 1) Cool the system to the ground state, 2) Specify two physical states as the encoding basis of
a qubit, 3) Implement logic gates by engineering encoding-specific interaction. In our recent works, we show
that all of these procedures are sufficient but not necessary. Specifically, we find a unified operation that can
implement logic gates for any encoding [2]. The formalism permits a new class of encoding that a pure logical
qubit is represented by a mixed physical state [1]. Because the purity of quantum system is not essential, the
requirement of ground-state cooling can be relaxed. Additionally, our formalism can reduce the initialisation
energy, and protect the logical qubit against a wider class of noise.

Vortragender

Dr. LAU Hoi-Kwan (Kero) is a visiting scientist at the Max Planck Institute for Physics of Complex
Systems, Dresden Germany. He was a Croucher Postdoctoral Fellow at the University of Ulm, where he
researched under the supervision of Prof. Martin Plenio. He received his PhD from the University of Toronto in
2014 with a thesis investigating the practicality of quantum information processing. Recently he proposed
schemes for universal continuous variable quantum computation without cooling, and universal quantum
computing with arbitrary continuous variable encoding (editor's suggestion in Physical Review Letters). He is
the receiver of multiple awards and published more than 15 papers in high impact refereed journals.